Write code in your favorite language and let Windows Task Manager represent a sine wave in CPU Usage History.
This is a technical in
Something like this:
while(true)
{
for(int i=0;i<360;i++)
{
// some code to convert i into radians if needed
...
Thread.Sleep(Math.Sin(i)*something_that_makes_it_noticeable_number_of_ms+something_that_makes_it_non_negative)
// some work to make cpu busy, may be increased to bigger number to see the influence on the cpu.
for(j=0;j<100;j++);
}
}